Apparatus for impregnating pourable material such as chips, shavings, and fibrous material



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O. F. WYSS ETAL 'SHAVINGS, AND FIBROUS MATERIAL Filed Oct. 10, 1950 APPARATUS FOR IMPREGN CHIPS June 24, 1952 Patented June 24, 1952 APPARATUS FOR IMPREGNATING 'POUR- ABLE MATERIAL SUCH AS CHIPS, SHAV- INGS, AND FIBROUS MATERIAL Oswald Fidel Wyss, Zurich, Switzerland, and Hans Peter, Strasbourg, France; said Peter assignor to said Wyss Application October 10, 1950, Serial No. 189,311 In Switzerland April 30, 1948 3 Claims. (01. 11856) The invention relates to apparatus for impregnating pourable material such as chips. shavings and fibers by sprayable material applied from nozzles.

In cases where a pourable material is to be wetted or impregnated with a high degree of uniformity yet with a minimum amount of an impregnating sprayable agent such as liquid, dissolved or emulsified materials or materials otherwise finely distributed in liquid, it is usually advantageous to apply the impregnating agents by means of one or several nozzles. The spraying of the impregnating agent from these nozzles is usually carried out in sealed apparatus, containers or chambers in order to avoid the escape of unused nozzle mists or vapors of the impregnating liquid. The material to be impregnated is repeatedly subjected to tumbling, mixing and distributing in order to expose it time and again to the spray for securing a uniform wetting of the individual particles from all sides. Some materials to be wetted are of such a character that care must be taken to prevent their texture and/or shape from being disturbed or otherwise detrimentally affected by the process. Therefore, such materials, usually in the form of shavings or fibers have been impregnated while they are slowly descending in the interior of a well or tower. This method has been used for instance, for impregnating materials that are capable of being deposited in loose layers or that, due to their low specific weight or their particular shape, will only slowly descend in an air space or will flutter or twirl when descending. When spraying such slowly descending materials, the spray nozzles are preferably applied from the side of the descending path. While for such materials many of the otherwise customary mixing, masticating and tumbling devices have been found to be of little advantage and, due to the action of their mixing, kneading and tumbling members, may even have a detrimental effect, the spraying of the downwardly fluttering material from lateral nozzles results in superior products and has the advantage that the twirling individual particles are wetted from all sides within a mostly well distributed flow of material.

This method, however, is less successful with fast descending materials and also requires a relatively large expenditure in space and equipment. Although it has been attempted to retard the descent of the material by agitating the air, such methods require intricate devices, and the air blown into the processing space for agitation causes air to escape at otherspots of the apparatus so that additional means are needed to liberate the escaped air from spray mists and other carried-off substances. In most cases the necessary wells, towers or the like devices have a considerable height, and it is often necessary to repeatedly pass the material through the tower or well before it is suliiciently impregnated. Besides, the side walls of the towers are also wetted by the sprayed liquids, and these liquids gradually run down along the walls and stick to them so that sometimes rather complicated cleaning accessories are required.

A similar impregnating process has also been carried out in horizontally arranged rotating drums in which the tumbling or rolling material is supposed to remain more or less continuously within the effective range of the spray cones of one or several nozzles. Such devices require considerably less space than tower type apparatus and permit the processing of material which would drop too fast to the bottom of a tower. The horizontal type equipment also affords a moderate, sometimes sufficient cleaning of the interior drum walls due to the friction of the rotating material. On the other hand, the nozzle spray in such apparatus impinges upon a much more densely distributed or even a packed heap of material as compared with the downwardly fluttering material processed in tower installations. Consequently, larger quantities of spraying liquid are required for wetting the material or the wetting may remain incomplete. Especially with material not fully dry or material which has already taken up a certain quantity of material, it may easily happen that the material will gather in heaps, bunches or lumps, this being especially the case with material of the readily interweaving or feltable type which, just on account of its interweaving or felting tendency, is especially desired in some industries such as the production of sheets and other solid bodies of chips or fibrous material by a more or less dry fabricating method. Such lumps of material occurring in horizontal drums hardly admit wetting liquids into their interior so that the resulting product is non-uniformily impregnated even if the lumps are subsequently subdivided.

It is an object of the present invention to provide apparatus having the advantages of the known tower and drum type impregnating apparatus while avoiding their above-mentioned disadvantages.

According to the invention, an impregnating apparatus for the above-mentioned purposes has a horizontal drum for receiving the material to be impregnated. The drum has a rotating cylinder wall and normally stationary end walls. Disposed within the drum is a rotating rake whose direction-oi rotation is opposed to that of the cylinder wall and whose rotating speed is considerably faster than that of the cylinder wall. The rake is adjacent to the upwardly moving portion of the cylinder wall. Alsodisposed within the drum are nozzleslewho'sespray cone covers the material thrown upwardly-by the 'rotating rake.

According to another feature of the invention, one or both of the stationary end walls of the horizontal drum accommodates the means for journalling the rotating rake and also the holding means for the nozzles or sets of nozzles. *According to a further feature, particularly-for continuously operating devices, one of the end walls of the receiving drum has an opening forthe introduction of the material to be impregnated w hile the other end wall has an opening for'the discharge ofthe "impregnated material, one or bothof the endwallsbeing preferably equipped withholding or supporting means for auxiliary accessories'if needed. "According to another feature of theinvention; the rotaryspeed and the relative height f the .rake are adjustable.

The foregoing and more. specific objects and features of the invention will be apparent from' the following description in conjunction with'the embodiments exemplified by the drawing, in which I Figure 1 is a schematic-front view on the intake side of a drum typeappa-ratus according tothe invention the -fro'nt endwall being omitted to show the interior of the drum,

Figure 2 is a schematic rear view of the same apparatus, i. e a view from the discharge side including-the appertaining rear end wall;

' Figures 3 and show in peripherally developed formdifferent-embodiments of a rake device pertaining to'the apparatus.

- The-apparatus according toFigure's 1 and 2 is moving portion -of-- the cylindrical wall. and rotatesin-thedirection-ofthearrow 3. The material is-charged into'the drum from the front side of Figure 1 and passes longitudinallythrough-the drum untilit isdischarged at the rear end shown in Figure 2. During this passage the-material Y is entrainedbythe rotating cylinder wall .of the drum, and whenmoving upwardly is caught .by the rake 3. and-then flungaway inopposition to the peripheraldrum' movement.- Consequently, the material is highly. agitated and passes,re-

' peatedly, in a good distribution through theeffective rangeof a'group of nozzles 5 before the. ma- ;terial again drops to the peripheralcylinder wall --to -be entrained toward the. rake for a repetition of the procedure. I 'At the same time, the dropping chip or fibro'us'material protects .thedrum --from collecting dirtL 'Ihefspray. direction ofthe -material'caught by the'rake drum can be determined or"cor'itrolled'bydeflector sheets. or baffles mounted inthe vicinity of the rake. --As..apparent from Figure v2, thefrear end wall 6"ofthedriinifwhiclilike the front wall is scaled against the rotating cylinder wall by suitable 4 sealing means, has a discharge opening bordered by an inwardly directed collector bafile 1. During the continuous operation of the apparatus the bafile 'l collects andguides the finished im- "pregnated material out ofthe discharge opening.

The bearing for the rake drum 3, shown in Figure 2 at B, is mounted on the rear end wall 6.

If, for instance when processing a very sticky impregnating"substance, a continuous cleaning of thedr'um wall is desired, a scraper or the like cleaning device .may be provided preferably above the rake and rotating in the same rotary sense as 'the rake while wiping over the drum wall. Q'This. rotating cleaning device, as shown at in Fig. 1, may consist of a brush roll or mayha'vesqueegeeor scraper blades or the like and is preferably designed to be readily exchangeable.

The bearings of such a rotating cleaning device are also mounted on the axial end walls of the drum. It is also readily possible to attachthe nozzle or nozzle sets or to-design S'the appertaining holding devices at the axial end "walls or theapparatus in'such a manner that the, nozzles or nozzle sets can readily beexchanged, which is of advantage especially for processing impregnating materials of pronounced stickiness. V The nozzles may also-be individually and exohangeablysecured to the appertaining supply pipes.

,As mentioned, apparatus according to the invention are well suitedfor continuous operation "over long'periods oftime. "For such an operation the material to be impregnated, arriving for instance, from a' conveyor band, is'conti nuously admitted through an opening in'the axial front wailof the drum 'or is dropped through the openm sol'that the treated material will continuously emerge from the'opening in the axial rear wall. In orderto-obtain a'gradual and continuoustravelof the material-alongthecylinder wall and along'the axis of the rotaryrake; a slight inclination of the drum toward the horizontal is preferable so that the rear wall of the drum is lower than the front wall. addition, some accessory 'means and-simplifications described in the following are favorably'applicable.

j The gradual and continuous travel "of the material to be impregnatedalong the drum, i. e.

in the axial direction of the rake drum can be cally represented in Figure 3 showing a peripheraldevelopment of; the rcylindric body that forms the core orhub portion of therakehnAs -shown in Figure 3, the rake core isequipped with a multitude of series of prongs, eachfserieslcomprising. three individualaligned prongs or. wires.

J..The prongsseries are disposedin a helical arrangement.

1 The individual active. members. of the rakealso I may be designedassmall ledges, beaterarms or spokes Lot-smaller. or "larger width in :order to increase the shovel action of "the :rake: device.

Such ledge shaped shovelling members may also be arranged on tnerake drum or core in a spiral or helical arrangement. -For instance, in-order to obtain a feed movement of the material parallel to the axial direction of the "drum and in addition to the main; feed movement, the justmentioned ledge, type spokes or beater arms =of larger-Tor smallerwidth. are preferabl Skewed relative to the core of the rake. Slanted or skewed shovelling members may also be mounted along the rake core in a spiral type arrangement in order to increase the feed movement of the material along the rake. Several arrangements of this type are shown in Figure 4 which also represents the peripheral drum or core surface of the rake in developed form along the plane of illustration. The section a of Figure 4 shows a normal arrangement of such ledges or shovelling members, i. e. these members are neither slanted nor helically arranged. Section D of Figure 4 shows a non-helical arrangement of similar shovelling members which, however, are slightly skewed relative to the rake axis. Section 0 of Figure 4 shows ledge members which are skewed and also arranged on a helix. The described arrangement of the rake members on the rake shaft or core body can be used alone or in conjunction with an inclined positioning of the drum relative to the horizontal. The time needed for impregnating the individual particles of the material in the drum depends upon, and can be determined from, the type or pitch of the helical arrangement of prongs, spines, wires and the like of the rake, the prong density in the helical arrangement, the degree of skew of the rake members and in some cases also the width of these ledge or spoke shaped members, also the length of the drum at a given cross section and the possibly applied angle of inclination toward the horizontal, and the like criteria relating, for instance, to the particular design and arrangement of the rake members. These various conditions are preferably chosen or adjusted in accordance with the particularities of the material to be treated in each case.

In conjunction with all above mentioned embodiments of apparatus according to the invention, and referring especially to apparatus for continuous operation, the discharge of the air supplied to the nozzles for spraying purposes can be combined with the introduction of the material to be impregnated preferably so that the discharge of this air occurs in a counterflow to the supply of material. This has the advantage that any residual mists or remainders of impregnating agent that may still be contained in the discharged air are more or less retained by the material to be impregnated and thus are salvaged with the eifect of not only cleaning the air to be discharged but also preimpregnating the material to be treated before it reaches the interior proper or nozzle zone of the drum.

We claim:

1. Apparatus for impregnating pourable material such as chips, shavings or fibrous material, comprising a substantially horizontal drum for receiving the material to be impregnated, said drum having a revolvable cylinder wall and normally stationary axial end walls, a rotary rake device of smaller diameter and higher rotary speed than said drum, said rake being disposed Within said drum adjacent to the upwardly moving portion of said cylinder wall and having a direction of rotation opposed to that of said drum for throwing the material upwardly toward the downwardly moving wall portion, and means for applying to the material a mist of impregnating agent,- said means comprising spray nozzles and having an air supply conduit and a supply conduit for impregnating agent connected to said nozzles, said nozzles being disposed within said drum laterally above the axis of said rake device and having a spray zone covering the zone in which the material is thrown upwardly by said rake device.

2. Apparatus for impregnating pourable material such as chips, shavings or fibrous material, comprising a substantially horizontal drum for receiving the material to be impregnated, said drum having a revolvable cylinder wall and normally stationary axial end walls, a rotary rake device of smaller diameter and higher rotary speed than said drum, said rake being disposed within said drum adjacent to the upwardly moving portion of said cylinder wall and having a direction of rotation opposed to that of said drum for throwing the material upwardly toward the downwardly moving wall portion, spray nozzle means for applying a mist of impregnating agent to the material, said nozzle means being disposed within said drum and having a spray zone covering the zone in which the material is thrown upwardly by said rake device, said drum being slightly inclined relative to the horizontal and having a charge opening at its higher end wall and a discharge opening at its lower end wall, and said. rake device having helically arranged rake members to impart to the material a feed movement toward said discharge opening.

3. Apparatus for impregnating pourable material such as chips, shavings or fibrous material, comprising a substantially horizontal drum for receiving the material to be impregnated, said drum having a revolvable cylinder wall and normally stationary axial end walls, a rotary rake device of smaller diameter and higher rotary speed than said drum, said rake being disposed within said drum adjacent to the upwardly moving portion of said cylinder wall and having a direction of rotation opposed to that of said drum for throwing the material upwardly toward the downwardly moving wall portion, spray nozzle means for applying a mist of impregnating agent to the material, said nozzle means being disposed within said drum and having a spray zone covering the zone in which the material is thrown upwardly by said rake device, a spraying air conduit connected with said nozzle means, and feed means for applying the material to be impregnated, said feed means having a supply conduit joined with one of said axial end walls and traversing said one end wall so as to permit waste air from. said nozzle means to escape through said supply conduit in counterfiow to the material.

OSWALD FIDEL WYSS. HANS PETER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,243,384 Lehrecke May 27, 1941 2,422,989 Skoog June 24, 1947 

